1. Field of the Invention
The present invention relates generally to interactive computer-implemented support solutions intended to facilitate the configuration of complex products having characteristics that are variable over a relatively wide range of possibilities.
2. Description of Related Art
When a customer orders or purchases a product, or a system of products, hereinafter collectively referred to as an artifact (e.g. a car, a truck or a computer), which has a plurality of selectable features, sub-components etc., it may be a very intricate and tedious task to find a combination of features that is both technically permissible and satisfies the customer's requirements (as well as applicable regulatory restrictions, such as maximum vehicle dimensions and axle weights). Moreover, the combinations of possible choices are often interrelated, such that for instance a particular gearbox can only be used together with certain engine types. Of course, depending on choices made at one stage, other choices to be made at a later stage may become irrelevant. For example, in the computer case, if a user chooses not to include a CD-ROM station in his/her PC, but instead opts for a DVD read/write station, he/she is not interested in having to specify a particular CD-ROM model in a later step in the configuration procedure.
U.S. Pat. No. 5,515,524 describes a method and an apparatus for configuring systems, which employs a generative approach. Here, configuration system with a model hierarchy is used, which is referred to as being a constraint-based. This approach renders it possible to define a model element as being contained in, or by, another model element. Consequently, logical and physical interconnections between various elements can be identified. However, the configuration engine operates in batch mode, i.e. it can only be applied to a complete set of parameters. This means that the mechanisms for selecting the parameters and the logic associated therewith are separated from the configuration model. As a result, only relatively low degrees of efficiency and user-friendliness are attainable.
U.S. Pat. No. 5,874,955 discloses an interactive rule-based system with selection feedback that parameterizes rules to constrain choices for multiple operations. This system may reduce the number of necessary choices. However, since at each stage, also options potentially incompatible with the configuration according to the prior choices are presented to the user, a latest made parameter selection can result in a rejection. Typically, this will irritate the user who then must step back a number of steps, and choose differently.
U.S. Pat. No. 6,336,110 describes a system for solving a constraint satisfaction problem (CSP) and constructing of a system, wherein a large CSP is divided into a plurality of subsets, which each only has two alternatives for each part. Allegedly, this division renders it possible to solve the large CSP relatively quickly. However, in practice, configuration problems often contain variables with very large domains, e.g. length. Therefore, this division-approach is not efficient. Namely, the number of subsets here becomes unrealistically large.
U.S. Pat. No. 6,223,170 reveals a solution for inference of partial knowledge in interactive configuration which enables configuration of a set of object values in a computer, e.g. in order to configure a car by choosing a specific combination of engine, paint, accessories, etc. The object values are here constrained by a rule base defining a number of relationships between the objects or the object values. Knowledge about undetermined object values is deduced by means of at least one interruptable algorithm. Thus, it can be determined whether a user selection of a part, or all of, the individual undetermined object values are possible or not. Nevertheless, the strategy proposed in this document is tightly linked to the configuration of a particular product having predetermined object values and constraints. In order to be applicable to the configuration of a different product the apparatus and the method performed thereby must be redesigned. Naturally, this is highly inflexible.
The published International Patent Application WO98/43160 describes another solution for configuring a number of parameters of a particular device, which is associated with the same type of inflexibility.
Hence, there exist numerous prior-art solutions that are capable of presenting a complex artifact configuration problem to a user in such a manner that the user is aided to configure the artifact in agreement with his/her requirements. However, there is yet no example of a solution, which on one hand, is capable of avoiding unnecessary queries and the risk of selecting incompatible combinations of parameters, and on the other hand, allows a high degree of flexibility with respect to the configuration problem to be solved.